A terminal device of this type can in particular be in the form of a shunt terminal, which is used to wire equipment and to distribute one or more electric potentials. A plurality of electrical lines can usually be connected to one shunt terminal, different connections of the shunt terminal being at one or more potentials.
A terminal device of the type in the present case comprises a housing that forms at least one contact cavity. A contact part is arranged in the at least one contact cavity, into which contact part the at least one electrical line can be plugged in order to make electrical contact with the contact part. In addition, a busbar is arranged on the housing, which busbar is electrically connected to the contact part and a busbar portion of which extends along a height line.
Shunt terminals are known, for example, from EP 2 393 160 A1, DE 10 2007 059 640 A1, WO 2009/052949 A1 and WO 2010/091984 A1.
In a terminal device in the form of a shunt terminal known from EP 2 393 160 A1, a plurality of contact cavities are formed in each case on different housing sides of a housing, in which contact cavities one contact part is arranged in each case. In this case, the contact cavities on one of the housing sides are connected in pairs to the contact cavities on the other housing side via busbars, such that the paired contact cavities are at the same potential.
The fundamental problem in terminal devices of this type in the form of shunt terminals is that, during operation, the terminal devices are exposed to changing environmental conditions when used, for example, in an industrial plant. Changes in temperature can thus occur on a terminal device, which changes in temperature lead to a spatial expansion of the various components of the terminal device, which can then be problematic in particular if different components expand to different extents due to different thermal expansion coefficients, thus resulting in a spatial change in position of the components relative to one another.
Owing to its elongate extension, a busbar expands along a height line, usually preferably along the height line. If, for example, the housing on which the busbar is arranged expands, when heated, in a manner different from that of the busbar, because the thermal expansion coefficient of the housing, which is for example made of plastics material, is different from the thermal expansion coefficient of the material of the metal busbar, the position of the busbar relative to the contact parts to which the busbar is connected can change, which can have an adverse effect on the electrical transition between the busbar and the contact parts.
For this reason, in the terminal device from EP 2 393 160 A1 for example, a compensation region is provided approximately in the center of each busbar having portions of the busbar which extend at an angle to one another and which function as a compensation device for compensating relative changes in length.
In a terminal device known from DE 10 2007 059 640 A1, a busbar comprises end portions that perpendicularly adjoin a busbar portion and are rigidly connected to contact parts.
In a terminal device known from WO 2010/091 984 A1, obliquely extended end portions adjoin a central busbar portion and establish a rigid connection to the contact parts arranged on the end portions.
The problem addressed by the present invention is that of providing a terminal device which makes it possible to compensate for relative changes in position due to different thermal expansion coefficients of components of the terminal device in a simple, cost-effective and space-saving manner and which can ensure a secure, reliable electrical connection of a busbar to associated contact parts in contact cavities.